<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <base href="/">
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="layui/css/layui.css">
    <style>
        #imgbox img{
            width: 100px;
        }
    </style>
</head>
<body>
<button type="button" id="uploadBTN" class="layui-btn">上传</button>
<div id="imgbox"></div>

<script src="layui/layui.all.js"></script>

<script>
    const upload=layui.upload;
    const $=layui.$;
    upload.render({
        elem:"#uploadBTN",
        url:"file/upload",
        done:function (result){
            let src=result.data[0].src;
            $("#imgbox").append("<img src='"+src+"'/>")
        },
        error:function (){}
    });
</script>

</body>
</html>